Snap switch-large air gap



Nov. 18, 1958 Filed Oct. 5. 1956 c. H. MILLl-:RwlsE 2,861,142

SNAP SWITCH-LARGE AIR GAP 2 Sheets-Sheet 1 Nov. 1s, 195s C. H.MILLERWISE SNAP SWITCH-LARGE AIR GAP Filed oci. 5. 195e 2 Sheens-Shee'I2 funn U INVENTOR, CARL Hem/AN ,t//LLEAl/Wse BY OLSEN, 5W/5 MW/15 UnitedStates Patent rCC? 2,861,142 SNAP SWITCH-LARGE AIR GAP Carl HermanMillerwise, Trumbull, Conn., assignor, by mesne assignments, to AmericanRadiator & Standard Sanitary Corporation, New7 York, N. Y., acorporation of Delaware Application October 5, 1956, Serial N o. 614,11511 Claims. (Cl. 20o-67) This invention relates to a vsnap switch inwhich a blade member may be moved with a snap action by a relativelysmall actuating force.

It is an object of this invention to provide an improved snap actingdevice that is simple in construction, sensitive in operation and whichhas a comparatively long service life.

vAnother object is to provide a snap switch wherein the switch blade isstressed during its installation in the switch in such manner as toreduce switch-fabrication costs and still insure uniform operatingcharacteristics in successive'switehes.

Another object of this invention is to provide an improved snap actingdevice which when actuated in one direction will return to its originalposition, when the actuating force is removed, or can be adjusted sowhen actuated in one direction will remain until actuated from theopposite direction.

A further object of my invention is to provide an improved snap actingdevice in which the actuating force required to operate the device isrelatively small and may be accurately regulated.

A vfurther object of this invention is to provide a slotted electricalswitch blade having snapping characteristics wherein the slot does notunduly increase resistance to current flow through the blade.

A still further object of this invention is` to provide an electricalsnap switch of the .foregoing character in which contact bounce is heldto -a minimum, and undue heating of the blade s eliminated. Y v iAnother object is to provide aswitch blade of the foregoing character inwhich the actuating forcefis imposed on the blade in such a manner as tocause a side contact roll effect on the snapping contact end of theblade, whereby to help prevent sticking of` said contact end on theContact members of the switch A still further object of this inventionis to provide a snap switch in which the supporting structure-for theblade can be adjusted to alter the magnitude of the snap spacedifferential fro-m one contact position to another.

Other objects of this invention will appear in the following descriptionand appended claims, reference being had to the accompanying drawingsforming a part of this specification wherein like reference charactersdesignate corresponding parts in the several views.

In the drawings: Y

Figure 1 shows a top View of one embodiment of an assembled snap switchof this invention. 'l

Figure 2 shows a side elevational view of the Figure l embodiment.

Figure 3 shows a blade usable in a second embodiment of the invention. Y

Fig. 4 is a view similar to Fig. 2 'but'taken after plungers 60 havedeflected bands 44 and 48 from vtheir Fig. 2 positions.

Fig. 5 is a sectional view on line 5 5 -in Fig; 1.

Before explaining the present invention in detail, it is to beunderstood that the invention is not limited in its application to thedetails of construction-and arrangement of parts illustrated in theaccompanying draw- V 2,861,142 Patented Nov, 11.8,' 1958,

ings, since the invention is capable of other embodiments.

bly of Figures l and 2 there is a terminal structure including asupporting structurev12 having'at one end a rst level 1 4 and a Asecondlevel 16, and at the other end a contact post 18 in which arevpositioneda rst contact member 20 connected to conducting element 22 and a secondcontact member 24 connected to conducting element 26. Contacts 20 and 24are spaced from each other by a relatively large .air gap to preventcurrent arcing thereacross. A f

A flexible switch blade 28 ris positionedY atwisey in the supportingstructure 12 with its contact end 30 and contact button 31 betweencontact members 20 and 24.. The terminal end 32 of blade 28 issandwiched between wall means shown as first plate member 34 and seconde plate member 36 and rigidly fastened to the iirst level I 44,46 and 48respectively.

14 of the stepped support structure -12 by means of screw 38. Blade 28has two central substantially parallel slots 40 and 42 therein whichdivide thevcentral portion of blade 28 into first, second, and thirdbands Plate member 34 is provided with a finger 50 extend- ,ingtherefrom and arching first away from and then into contact in a concavemannerY with the second band 46 of blade 28. Finger 50 presses band 46in the direction of support 12 and provides force means on band 46tending to prevent section 46 from bowing with sections 44 and 48 .insuch a manner that vthe contact end 30 would move in a direction towardcontact member 20.

Plate member 36 is pressed between blade 28 and first level 14. Member36 is provided with two iingers 52 extending therefrom in a relativelyrigid manner iirst Yinto convex contact with bands 44 and 48 near theirterminal ends and second away from the bands 44 and 48 into contact withthe first level 14. These iingers provide force means to deect bands 44and 48 out of the plane of band 46, thereby urging contact end 30 ofblade 28 resiliently against contact member 20. Thus as shown in Figure2 bands 44 and 48 tend to bow in a direction toward contact member 20and band 46 tends to bow in the opposite direction.

Plate member 36 also is provided with a finger S6 extending therefromrst away Afrom the blade 28 into convex contact with the second level 16of the terminal support member and second away from the second level 16to be in concave contact with a point on second band 46 near its contactend 30. Finger 56 provides force means on band 46 tending to prevent thecentral portion, of band 46 from moving in a directionvr toward level16.

In operation of the Figure 1 snap switch, when a force in the arrow 59direction is applied to-bands 44 and 48 through the mechanism ofreciprocable plungers 60, the direction of the resultant forces in bands44, 46 and 48 'will be changed; band 46 will buckle over finger 56 andthe contact end 30 will be caused to snap from contact member 20 intocontact with member 24, as shown by the dotted lines in Figure 2. Fig. 4shows the positions of the bands as the contact end 30 is just beginningto snap from member 20 toward member 24. On upward movement of plungers60, the primary deflecting force at 52 will cause the contact end 30 tosnap back into its original position. The snapping characteristics ofblade 28 may be adjusted by presetting the point of contact finger 56has with band 46 toward and away from level 16.

If desired there may be employed a switch blade such purpose ofl de-j asblade 28a depicted in Figure 3 wherein there is a single central slot40a forming first and second band portins 44a and 46a separating thecontact end portion 30a from the other end portion 32a. Blade 28a isadapted for installation in a switch structure (not shown) which isgenerally similar to structure 12 except for the structuralmodifications thereof necessary to support a two band section bladeinstead `of a three band section blade. When blade 28a is installed onits supporting structure a slight twisting motion will be given to theblade and an actuating force .applied to blade portion 44a through themechanism of a plunger 60a, and the contact end 30a will be deflectedslightly in a sidewise direction from band 44a to band 46a. This sidecontact roll effect can be accentuated as shown in Figure 3by'oi-centeringly positioning contact button 31a in alignment with band46a iustead of in alignment with slot 40a. In this manner possibility ofsticking of the contact end of the blade at the contact members may bereduced.

It is a preferred feature of the invention to have the slots (4l), 42 or40a) closed ended, i. e. completely surrounded by blade material. fInthis way there is continuous unimpeded material for flow of electricalcurrent through the blade. Thus having no slots running crosswisethrough the blade improves the current llow characteristics. t

It will be noted that prior to their installation on their supportingstructures, both blades 28 land 28a are flat unstressed stampings. Bladestressing is accomplished wholly by turning down of screw 38. Thismethod of bladeV stressing has been found to reduce switch-fabricationcosts while still insuring uniform operating characteristics insuccessive switches.

I claim:

1, In a snap switch: a terminal structure having first and second spacedcontact members at one end and a terminal structure at the other end; acontact blade having a contact end disposed between the said contactmembers, having an opposite terminal end connected to the said terminalstructure and said blade being slotted to form first and second bands;first force means acting on said first band near its terminal endtending to urge said Contact end of said blade resiliently against saidfirst contact member; `second force means acting on said second bandnear its terminal end tending to prevent said band from moving in thedirection of said first force; third force means acting on `sa-id secondband near its said contact end tending to prevent said band from movingin substantially the opposite direction as said first force; and fourthforce means adapted to act on said first band between the said firstforce means and the contact end of said first band-in substantially theopposite direction as said first force so that the contact end of saidblade will snap from said first contact member to said second contactmember when said fourth force is applied.

2. In a snap switch: a terminal structure having first and second spacedcontact members at one end and a terminal member at the other .endg acontact blade having a contact end disposed between said Contactmembers, having an opposite terminall end connected to said terminalmember and having an elongated slot therein in a direction substantiallyparallel to a line joining the said two blade ends to form first andsecond bands therebetween; first force means acting on said first bandnear its terminal end tending to urge said ,contact end of said bladeresiliently against said first contact member; second force means actingon Said second band near its terminal end tending lto prevent said bandfrom moving insubstantially the same direction as said first force;third force means acting on said second band near its said contact endtending to lprevent said band from moving in substantially the oppositedirection as said first force; and fourth force means adapted to act onsaid first band between said first and third force means insubstantially the opposite direction as said first force, lso that thecontact end of said blade (-1) will snap from said first contact memberto said second contact member when the said fourth force is applied and(2) will snap back to said first contact member upon removal 4of saidfourth force.

3. The snap switch of clairn 2. wherein the contact end of the blade hasa contact button in alignment with said second band so that when saidfourth force means is applied to said first band the side contact rolleffect on the Contact end is thereby accentuated.

4. In a snap switch: a terminal structure havingrst and second spacedcontact members at one end and a terminal support member at the otherend; a slotted contact blade having a contact end disposed between thesaid contact members, having an opposite terminal end connected to thesaid terminal support member and having two central slots therein in adirection substantially parallel to a line joiningthe two blade ends tofqrm rst, second and third bands therebetween; first force means actingon said first and third bands near their terminal end tending to urgesaid contact end of said blade resiliently against Said first contactmember; second force means acting on said second band near its terminalend tending to prevent said band from moving in substantially the samedirection as said first force; third force means acting on said secondband near its contact end tending to prevent said band from moving insubstantially the Opposite direction as Said first force; and fourthlforce means adapted to act on said first and third bands between saidfirst and third force means in substantially the opposite direction assaid first force, so that the contact end of said blade (l) will snapfrom said first conta-ct member when the said fourth force is appliedand (2) will snap back to said first contact mem-ber upon removal ofsaid fourth force.

5. A snap switch comprising: a terminal structure having first andsecond spaced contact members and a terminal support member at the otherend having rst and second levels; a slotted contact blade having acontact end disposed between the said contact members, having anopposite terminal end connected to said first level of said terminalsupport member and said blade being slotted to form first and secondbands each having first and second opposite faces; said terminal supportmember having rst and second plate members, said second platememberbeing pressed by the blade terminal end against said first level,having a first finger extending first into contact with the second faceof the first band near its terminal end and second away from said secondface into contact with the said first level, and said secondplate'member having a second linger extending first away om the bladeinto Contact with said second level of saidterminal support member andsecond away from the said second level to be in contact with the secondface of the second band near its contact end, and said first platemember pressing the blade terminal end against the said first level andhaving a finger extending first away from and then into Contact with thefirst face of the second `band near its terminal end; so that (l) whensaid first band is depressed in a direction toward the said second levelthe contact lend of the blade will snap from the said first contactmember to the said second contact member and (k2) when the said firstband is no longer so depressed the contact end will snap back to saidfirst contact member.

6. A snap switch comprising: a terminal structure having first andsecond spaced contact members and a terminal support member at the otherend having first and second levels; a slotted contact blade having acontact end disposed between the said contact members, having anopposite terminal end connected to said first level of said terminalsupport member and said blade being slotted to form first and secondbands each having first and second opposite faces; said terminal supportmember having first and second plate members, said second plate memberbeing pressed by the blade terminal end against said first level, havinga first finger extending rst into contact with the second face of thefirst band near its terminal end and second away from said second faceinto contact with the said first level thereby tending to urge saidcontact end of said blade resiliently against said first contact member,and said second plate member having a second finger extending first awayfrom the blade into contact with said second level of said terminalsupport member and second away from the said second level to be incontact with the second face of the second band near its Contact endthereby tending to prevent said second band from moving in a directiontoward said second level, and said first plate member pressing the bladeterminal end against the said rst level and having a finger extendingrst away from and then into contact with the first face of the secondband near its terminal end thereby tending to prevent said band frommoving in a direction away from said first level; so that (1) when saidrst band is depressed in a direction toward the said second level thecontact end of the blade will snap from the said first contact member tothe said second contact member and (2) when the said first band is nolonger so depressed the contact end will snap back to said first contactmember.

7. A switch comprising: a support structure; a contact blade positionedfiatwise in said support structure; said blade being slotted to definefirst and second spaced band sections interconnected at the contact endof said blade; said support structure including first and second wallsclamping the other end of the blade therebetween, said second wallprojecting into the at plane of said first section whereby to deformsaid first section out of the general blade plane and develop aresultant force in the first section tending to deflect said contact endin the direction of the deformed section, said second wall being inengagement with said second section near its contact end, and said rstwall being in engagement with said second section near its said otherend; and a portion of the rst section adjacent the contact end being outof registry with the support structure, whereby when a force is directedagainst said portion in opposition to the force of said deforming wallsaid portion is forced to move through the plane of the second sectionso as to change the direction of said resultant force, thereby causingsaid engaging wall means of said second section to buckle the secondsection in the direction of the deformed section and snap the contactend in a direction away from the deformed section.

8. A switch comprising: a support structure; a contact blade positionedflatwise in said support structure; said blade being slotted to definerst and second spaced band sections interconnected at the contact end ofsaid blade; said support structure including rst and second wallsclamping the other end of the blade therebetween, said second wallprojecting into the fiat plane of said first section near its said otherend whereby to deform said first section out of the general blade planeand develop a resultant force in the first section tending to deect saidcontact end in the direction of the deformed section, said second wallbeing in engagement with said second section near its contact end, andsaid rst wall being in engagement with said second section near its saidother end; and a portion of the first section adjacent the contact endbeing out of registry with the support structure, whereby (1) when aforce is directed against said portion in opposition to the force ofsaid deforming wall said portion is forced to move through the plane ofthe second section so as to change the direction of said resultantforce, thereby causing said engaging wall means of said second sectionto buckle the second section in the direction of the deformed sectionand snap the contact end in a direction away from the deformed section,and (2) when said force is removed from said portion the contact endwill snap back to its originally defiected position.

9. A method for imparting snapping character to a slotted blade having acontact end and depending therefrom first and second bands and anotherend adapted to be positioned in a support structure, which comprises:imposing a first force means on said first band near its said other endtending to deflect said contact end in the direction of said firstforce; imposing a second force means on said second band near its saidother end tending to prevent another end portion of said second bandfrom moving in the direction of said first force; imposing a third forcemeans on said second band at a point near its contact end tending toprevent said point of said second band frommoving in a directionopposite to said first force; and having a fourth force means adapted tobe imposed on said first band between the said first force means and thecontact end of said band in a direction opposite to said first force,thereby causing said third force means to buckle said second bladesection between its contact 'end and the second force means in thedirection of the first force and snap the contact end in a directionopposite to said first force.

10. A method for imparting snapping character to a slotted blade havinga contact end and depending therefrom first and second bands and anotherend adapted to be positioned in a support structure, which comprises:imposing a first force means on said first band near its said other endtending to deflect said contact end in the direction of said firstforce; imposing a second force means on said second band near its saidother end tending to prevent another end portion of said second bandfrom moving in the direction of said first force; imposing a third forcemeans on said second yband at a point near its contact end tending toprevent said point of said second band from moving in a direction`opposite to said first force; and having a fourth force means adaptedto be imposed on said first band between the said first force means andthe contact end of said band in a direction opposite to said firstforce, so that (1') imposition of said fourth force thereby causes saidthird force means to buckle said second Ablade section between itscontact end and the second force means in the direction of the firstforce and snap the contact end in the opposite direction of said firstforce, and (2) removal of said fourth force thereby permits the contactend to snap back into its original deflected position.

11. A switch comprising support structure; a blade positioned fiatwiseon said support structure; said blade having a slot therein to definerst and second spaced blade sections and a third vblade sectioninterconnecting said first and second support structure including twowalls clamping a portion of the blade therebetween, one of said wallsprojecting into the plane of the first section but engaged with thesecond section whereby to deform said second section out of the plane ofthe first section and develop a first force in the second sectiontending to deflect the third section in the direction of the deformedsection; a portion of the second section adjacent the third sectionbeing out of registry with the support structure, whereby when a forceis directed against said portion in opposition to the first force saidportion is forced to move through the plane of the first section so asto change the direction of the first force, thereby causing the firstblade section to buckle in the direction of tle deformed section andsnap the third section in a direction away from the deformed section.

References Cited in the file of this patent UNITED STATES PATENTS1,960,020 McGall May 22, 1934 2,697,145 Winet Dec. 14, 1954 2,700,079Haydon Jan. 18, 1955 .FOREIGN PATENTS 567,614 Great Britain Feb. 23,1945

